Loop aerial



Oct. 7 1924.

J. H. ROGERS LOOP AERIAL Filed July 12, 1923 3 Sheets-Sheet 1 gvwenfozOct. 7, I924. 1,510,799

J. H. ROGERS LOOP AERIAL Filed July 12, 1923 .3 Sheets-Sheet 2 Get. 71924,

, 1,510,799 J. H. ROGERS LOOP AERIAL Filed July 12, 1923 3 Sheets-Sheet5 85% @Vza, wmfla w for "n 5" Patented (Dot. 7, 33.24.

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Application flied July 1.2, $523., Serial 1%. 651,085).

Georges and State of Maryland, have in- -vented certain new and usefulimprovements in Loop Aerials of which the following is a specification.

' v The present invention is based on a loop antenna structure whichpossesses great advantages over the ordinary form. The underlyingfeature of this antenna is that a multiple turn loop is arranged withits conductors substantially in the surface of a tore whereby a verycompact form of antenna is produced, which nevertheless has a very lowdistributed capacity.

in m prior application, Serial No. 607,623, filed December 18, 1922, Ilntve disclosed a loop antenna, the turns of which are arranged in apolygonal helix. "While one form of the present device resembles theformer in that the loop conductor comprises a plurality of strandsconnected in parallel but spaced from each other except at their ends,it differs from the prior construction in that the conductor is arrangedon a polygonal tore instead of as a helix. This results in a greateconomy of space and slim plicity of construction. An antenna of thepresent form is also much easier to manipulate and of substantially thesame electrical elliciency as the prior type, forthe same amount of wireused.

A simpler type of the tore-shaped loop is also embodied in one form ofthe present invention, wherein a single conductor is substituted for thecomposite one.

A process of making the tore-shaped loop antenna is another feature ofthe present invention.

For a fuller understanding of the invention, reference should be made tothe fol lowing specification descriptive of the preferred forms of" thedevice, in connection with the accompanying drawings, where- Fig. 1 isan elevation of a loop;

Fi 2 is a fragmentary diagrammatic detail of part of the loop shown in-1 showing the type of winding;

Fig. 3 is a diagram of the means used in winding the loop of Fig. 1;

Fig. i is a detail view of a stack of the spacing disks as arranged tofacilitate the operation.

Fig. 5 shows a modified loop similar to that shown in Fig. 1 except thata single conductor is used in place of a composite one.

Referring first to Figs. 1 and 2, there is shown an antenna comprising acomposite conductor 1 formed into a multiple turn loop, and having itsends at binding posts 2 and 8. The composite conductor consists of aplurality of strands, eight being illustrated in the present case, andthe loop also comprises eight turns. The loop is supported by aplurality or" radial arms a each of which is slotted at its inner end asshown at 5. Screws 6 passing through the slots 5 serve tosecure thesearms -adjustably to the central hub or disk 7, as shown. A verticalsupport or rod 8 journaled at 9 in the hub 7, as shown, is itselfsecured to the base 10. A brace 11 is secured to two of the arms l,which may be made longer than the rest, by means of screws 12 passingthrough slots 13. This brace 1.1 has an aperture 14 fitting the rod 8loosely, so that the whole structure may rotate about said rod 8. Apiece of insulation 15 may be provided as a mounting for the bindingposts 2 and 3.

Each arm l has a slot 18 at its outer end. Supports 16, best shown inFig. 2, are held in these slots, by means of screws 17. As illustrated,these supports are circular disks but the shape is subject tomodification within wide limits. Each support 16 carries a plurality ofconductor holding disks 18, which are secured to the supports 16 byscrews 19. These disks 18 are provided with a plurality of holes, a, Za, d, e, 7', g and h, as shown, to receive the strands of conductor. Inthe present form, these holes are arranged in circular series. Each disk18 also has a hole 1'? for the screws 19.

It will be noted that the composite conductor comprises eight strands,each strand being held in one of the holes in each disk 18. A cage isthus formed similar to the cage of the prior application hereinabovereferred to. This composite conductor passes successively around thesupports, and when the whole is wound, it will be seen that the turns ofthe cage itself form a still larger cage. The strands are transposedregularly in their courses from. disk to disk and the cage is alsotransposed around sup ports 16, as best shown in Fig. 2, in a $11111 larmanner so that in the finished device all the strands are substantiallysymmetrically lltl mi ii any more metrical l larger J oi a ms, thecloser will be t a. true circular ln order i transposing the wersections oi the cage,

which adjacent to said red as shown in 1 fa wit the loop just described,the preferred ,y to provide a plurality of reels of wire, 20, equal innumber to the number of strands in a cage, eight as shown in ig'. fl.llhe entire number of disks 18 is then assembled as in Fig. l, with theWire holes in register but with the screw receiving holes 21successively displaced, as shown, by dotted lines. The eight strands arethen threaded through the Whole set of disks as in 3. Then the disks 18are Secured by their screws 17, one at a time, to the appropriatesupports 16, whereby the strands in the cage become transposedautoniaticallyin the mere operation of Winding; the loop.

Referring now to Fig. there is shown a simpler type of loop wherein asingle conductor is provided in place of the cage. This figure showsdiagrammatically a plurality ot radial arms 22 supported by a hub 23,journalled on rod 8. Rod 8 is held by base 10, and passes looselythrough brace Q/a which is secured to two of the arms 22, and holds thebinding posts 2 and 3. Each arm supports a disk 25 which is aperturedto. support the conductor 26. This conductor is threaded through saidapertures, as shown at j, It, Z, m, n, o, and g0, and may be andpreferably is, transposed from disk to'dislr as in the other type.

'Wliile l have disclosed a loop wherein the conductors are transposed tosecure a high degree oi electrical symmetry, and.

prefer such construction, it will be evident that for certain purposesvery satisfactory results ma be secured without such trans position andthe invention is therefore not to, be considered as limited to theactual forms disclosed.

What l claim is:-

1. An antenna comprising a conductor formed into a multiple turn loop.all the turns oi the loop lying substantially in the surface of apolygonal tore.

2. An antenna comprising a composite conductor formed into a multipleturn loop, all the turns of the composite conductor as a Wholelyingsubstantially in the surface of a polygonal tore,

3. An antenna comprising .a conductor formed into a multiple turn loop,said'conductor having each turn disposed symmetriit pr is ed. to'oinitdoctor having each turn disposed substantially in its surfaceof apolygonal tore, the conductor i comprising a plurality of parallelstrands arranged in cylindrical surface,

i -tn antenna comprising a so duct-or consisting of a plurality otequidistant pen allcl strands which are successively transposed, saidconductor being formed into a multiple turn loop wherein the turns aredisposed substantially in the surface of av polygonal tore and arethemselves successively transposed so as to be distributed symmetricallyover said surface,

6. A; loop antenna comprising a conductor consisting of a plurality ofstrands electrically connected in parallel but spaced from one another,said conductor as a Whole beingfiormed into a multiple turn coil Whereinall the turns are substantially symmetrically arranged with respect toone another.

7. A loop antenna conun'ising a composite hollow conductor, saidconductor between its terminals consisting of a plurality of strandseach spaced from its neighbors, and

each disposed on a path which is substan tially helical with respect tothe hollow conductor, said conductor itself being formed into a hollowassembly wl'ierein all the turns are spaced symmetrically from theirneighbors.

8. A multiple turn loop antenna comprising a support, radial armscarried thereby, a perforated spacer carried by each arm, theperforations in each spacer beingsub-stau tially uniformly spaced in aclosed curve and a conductor traversing the spacers in succession andpassing through all the perforations in its complete course about theloop,

9). The process of making acage-loop antenna having perforated spacersfor the conductors constituting the cage, which process comprisesthreading the requisite number of spacers on the individual conductorsbefore the winding operation is started.

10. The process of making a'cage-loop antenna having g'ierloratedspacers for the conductors constituting: the cage, said spacers hayingaligning means therein, which process comprises threading the resin sitenumber of spacers on the individual conductors with the aligning meansprogres sively turned whereby the cage when assembled will have theconductors automatically transposed symmetrically.

ln testimony whereof l affix my signature.

' JAMES lElTAllRlS ill

